Amprobe (Meterman) LM631A Digital Light Meter

Background

This is the light meter that's most
commonly used on Candle Power
Forums to measure the light output of flashlights.
I
think
there are two reasons for this, one the meter seems to have
reasonable calibration and two, it has a 2.5 mm socket with a mv analog
signal output that can be connected to an external meter or data logger.

Ranges

This is not an auto ranging instrument,
if you get "OL" you must manually press the RANGE button.
Each press upranges the meter and when on the highest range cycles back
to the lowest range.
20.00, 200.0 & 2000 lux
20.00, 200.0, 2000 & 20000 fc

Power

There are four AAA batteries in the
long handle. But for long flashlight light vs. run time tests it
would be nice to have an easy way to use external power. That
might be donw by replacing the 2.2 mm external analog output jack with
a stereo version.